Galileo's UTC compared to 'actual'' UTC

The current ‘offset’ between GST and the approximation of UTC (the final measurement of UTC is so precise it is actually calculated weeks afterwards) is determined by Galileo’s Time Validation Facility (the precursor of the Galileo Time Service Provider), which is currently operated by the company GMV in Madrid, Spain. This process means UTC time measurements can be made available to users to within an designed accuracy of 26 nanoseconds, although in practice Galileo has been able to do better than this – down to about 5–10 nanoseconds.